Advanced communications systems have brought portable radiotelephony to countless subscribers throughout the world by combining many technologies such as high frequency semiconductors, computer and communications technology. As the technology matures it opens opportunities for expanded services such as personal digital assistants.
The personal digital assistant (PDA) is essentially a portable electronic computer having specialized capabilities. The PDA comes in several varieties such as message pads, palm top computers and those that combine PDA's with communications units. Generally, PDA's do not have self contained phone units, however, a user may still send telefaxes, electronic mail(E-mail), voice mail and voice telephone calls. Some PDA's can be directly connected to a the Public Switched Telephone Network(PSTN) whereas others may require an adapter such as a PCMCIA card. It is a common practice to include features such as calculators, calendars, memorandum pads and personal and business directories or calling card file information. PDA's that contain such information utilize conventional computer storage facilities and retain such information in non-volatile memory storage devices such as random access memory, tape storage, and magnetic disk storage.
Regardless of the particular data storage technology, the information is accessible to the user of the PDA's through conventional display technology, such as a liquid crystal display. The personal and business information contained often includes such information as individual names, company names, addresses, telephone numbers, telefax numbers, E-mail addresses and other wide ranging information.
Through advances in storage technology, PDA users compile ever increasingly more information imposing requirements to retrieve specific information rapidly and accurately. However, simply increasing electronic processor speed often taxes available power sources, but, because the devices are required to be small enough to be portable, large power supplies are not feasible. This dual need challenges the designer of this technology to strive for innovative methods for producing the required searches efficiently which calls for improving computer data base search techniques.
A PDA may contain memory storage devices to permit the creation of data bases used in various PDA and telephone applications. For example, the data base may hold contact information, similar to a calling card, such as telephone numbers and addresses. This contact information may be used by the telephone to initiate a telephone call, telefax or E-mail transmission. The PDA can then send and receive message content contained within mediums such as the telefaxes or E-mail and serve as an adjunct to the telephone to provide speakerphone or voice mail capability. As the number of contact entries becomes large it becomes necessary, for practical reasons, to incorporate methods to search the data bases for information the user needs to retrieve.
To accomplish a search the PDA would have to incorporate software or firmware to properly interpret the search commands, carry out a search algorithm, and display lists of records that meet the search specification. Such methods are generally well known by those person skilled in the computer arts.
For smaller data bases such as are utilized in PDA applications, the approach has been to provide a simple search, where the user activates the search function and types in the search key or designator. The search is performed after the user activates the search by, for example, pressing a key such as enter or a specific `search` key. This is referred to as a `passive search` and is characterized by the fact that it does not display the result of the query as soon as the query search key activates the search.